III. THE LEAF. 5 1 



is dissolved. So I shall henceforward speak simply 

 of the leaf and its ribs, — only specifying the addi- 

 tional veined structure on necessary occasions. 



10. I have just said that the ribs — and might 

 have said, farther, the stalk that sustains them — are 

 knit out of the tissue of the leaf. But what is the 

 leaf-tissue itself knit out of? One would think that 

 was nearly the first thing to be discovered, or at 

 least to be thought of, concerning plants, — namely, 

 how and of what they are made. We say they 

 ' grow.' But you know that they can't grow out of 

 nothing ; — this solid wood and rich tracery must be 

 made out of some previously existing substance. 

 What is the substance? — and how is it woven into 

 leaves, — twisted into wood ? 



11. Consider how fast this is done, in spring. 

 You walk in February over a slippery field, where, 

 through hoar-frost and mud, you perhaps hardly 

 see the small green blades of trampled turf. In 

 twelve weeks you wade through the same field up 

 to your knees in fresh grass ; and in a week or two 

 more, you mow two or three solid haystacks off it. 

 In winter you walk by your currant-bush, or your 

 vine. They are shrivelled sticks — like bits of black 

 tea in the canister. You pass again in May, and 

 the currant-bush looks like a young sycamore tree ; 

 and the vine is a bower : and meanwhile the forests, 



